Up until this time a real problem has been the provision of efficient and effective means for the monitoring of traffic flows and, in particular, the speed of traffic travelling along public roads. Until very recently, radar systems have generally been acknowledged to be the most accurate speed measuring devices but they suffer from a number of major drawbacks, such as their high capital cost and their inability to positively identify the source of the speed reading.
Amphometers based on so-called `treadle` switches, or on pneumatic cables, are cheap and still reasonably accurate but also suffer from a number of disadvantages. The switches themselves have poor triggering characteristics when activated by a passing vehicle, necessitating a large distance between the two required sensors in order to make an accurate speed reading. This makes them cumbersome to install, since two separate sensors must be laid on the road surface with a distance usually greater than three meters separating them.
Amphometers also suffer from their inability to identify the positions of vehicles on a road surface. Moreover, their flimsy construction makes them wholly unsuited as a road based sensor unless a very short working life can be tolerated.
By way of contrast, in the present invention, the configuration of the strip and its pressure switches allows the contact means to be spaced apart by a distance as small as, say, ten centimeters.
Policed traffic surveillance and control is extremely costly, relying on a considerable number of officers to enforce the road rules. Technology has provided some answers such as radar-based speed measuring devices and loop detector-based traffic camera installations. Both systems are expensive, with radar-based systems generally requiring an operator. Radar/camera systems do exist but because of their high cost and vulnerability to vandalism are rarely operated unmanned.
The inefficiency of these surveillance systems has made it impractical to deploy large numbers of enforcing agents in the field.
It is therefore an object of the present invention to overcome the above and other disadvantages by the provision of a simple, cheap but efficient traffic monitoring system capable of being deployed in large numbers so as to obviate the need for a high level of police surveillance. Other objects of the invention will become apparent from the following description.